Age distorts the interpretation of FIB-4

Area of Science:

• Hepatology
• Diagnostic Accuracy
• Biomarker Validation

Background:

• Non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) are significant health concerns.
• Accurate non-invasive markers for liver fibrosis are crucial for patient management.
• The FIB-4 index is a widely used biomarker for assessing liver fibrosis.

Purpose of the Study:

• To investigate the influence of patient age on the diagnostic performance of the FIB-4 index.
• To determine if the likelihood ratios (LRs) derived from FIB-4 values are age-dependent.
• To assess how age affects the accuracy of FIB-4 in distinguishing between different stages of liver fibrosis.

Main Methods:

• Analysis of a dataset of 540 patients with NAFLD or NASH, categorized by liver biopsy results (no/early vs. advanced fibrosis).
• Parametric modeling to establish the relationship between the natural logarithm of FIB-4 (log(FIB-4)), age, and standard deviation (SD).
• Calculation of the area under the ROC curve (AUC) and likelihood ratios (LRs) as functions of age.

Main Results:

• Mean log(FIB-4) increased with age in both fibrosis groups.
• No significant change in the standard deviation of log(FIB-4) with age was observed.
• A trend towards decreased diagnostic accuracy with increasing age was noted, though not statistically significant.
• Likelihood ratios (LRs) for specific FIB-4 values were found to decrease with age.
• AUC was 0.73 when accounting for age, versus 0.79 without age adjustment.

Conclusions:

• Age significantly influences the interpretation of FIB-4 test results.
• Age-related changes can distort the estimated diagnostic accuracy and likelihood ratios of FIB-4.
• Clinical application of FIB-4 may require age-specific considerations for accurate fibrosis assessment.